Climate Outlook:

American Samoa is now entering the onset of its next rainy season. Rainfall through April 2007 is expected to be near to above normal. The effects of ENSO on the rainfall in American Samoa are somewhat less defined than in Micronesia. Additionally, the effects of ENSO tend to appear later in American Samoa than in Micronesia, due to it’s location. The threat of a damaging tropical cyclone is greatest during weak El Niño conditions. Beginning in November 2006 and continuing through April or May of 2007, the threat of a damaging tropical cyclone passing near any of the islands of American Samoa is increased. During strong El Niños, the cyclone paths shift eastward into French Polynesia, and during La Niña, the cyclones tracks are shifted westward into the Coral Sea. With most climate models indicating a trend toward weak or moderate El Niño conditions through early 2007, it would be prudent for American Samoa to begin contingencies for a busy cyclone season. At least two or three tropical cyclones are expected to pass close enough to American Samoa during this period to bring episodes of heavy rainfall and gale force northwesterly winds into it’s territorial waters. While a direct strike is not anticipated, the risk of a damaging hurricane is higher than normal.

Predicted rainfall for American Samoa from November 2006 through September 2007 is as follows:

source: UOG-WERI